Printed publication DE 10 2010 051 954 B3 discloses a circular connector which is configured, on the terminal side, for contact connection on a printed circuit board. For the transmission of a plurality of independent differential signals, electrical contacts are arranged in pairs in the connector.
For the damping of crosstalk between the signal pairs, an electrically conductive cruciform shield is provided, which is connected to at least one ground terminal of the printed circuit board in an electrically conductive manner. This is enclosed by a likewise cruciform contact carrier, in the obliquely configured inner edges of which locating grooves are provided for the accommodation of electrical contacts. The electrically non-conductive circular body is push-fitted over this cruciform arrangement and, in turn, is ultimately enclosed by an electrically conductive connector housing.
It is further disclosed that the insulating circular body, approximately midway along its length, incorporates a circumferential groove, in which an annular and electrically conductive helical spring is inserted. This can be electrically contact connected, firstly with the cruciform shield at the latching moldings thereof, by means of two mutually opposing longitudinal slots in the circular body. Secondly, the helical spring can be contact connected with the electrically shielding connector housing which encloses the circular body. The connector housing can be incorporated in an electrically conductive device housing in the form of a front panel insert, and is connectable, on the plug-in side, with a mating connector which is inserted from the exterior.
In practice, however, it has emerged that the shielding connection by means of the above-mentioned helical spring, upon the plugging-in of the electrically conductive connector housing, generates relatively high assembly forces. Moreover, the conductive behavior of the helical spring, on the grounds of the relatively small electrical contact surface vis-à-vis the connector housing and the cruciform shield, is not ideal. The structural necessity for a circumferential annular groove can also adversely affect stability and the available space for other structural features in the circular body.
By way of an improvement, printed publication DE 10 2012 105 256 A1 proposes the employment of an open spring washer. The spring washer has an appropriate outline for the electrical contact connection, firstly of the cruciform shield and secondly of a connector housing in which the insulating body is inserted, and thus for the electrically conductive connection thereof.
However, the use of a spring washer of this type is associated with a disadvantage, in that a groove is also required in the circular body for this purpose. This can be configured to a somewhat narrower width than in the case of the above-mentioned helical spring configuration, and is not required to run entirely around the insulating body. It has further emerged that, even in this configuration, the force associated with the plugging-in of the connector housing is not optimally transposed, as the spring washer also assumes a somewhat inclined and potentially tilted position, rather than, as required, extending exclusively towards the interior, in order to constitute the electrical contact with the cruciform shield. The effective contact surface thereof, vis-à-vis both the housing and the cruciform shield, at the corresponding contact points, is also somewhat small, which impacts negatively upon the electrical conductivity of this shielding connection.
The German Patent and Trademark Office, in the priority application with respect to the present application, has investigated the following prior art: U.S. Pat. Nos. 5,029,908 A, 4,938,714 A and US 2006/0125235 A1.